Combined dust-catcher and blast-heater.



No. 720,257. 7 PATENTED FEB. 10, 1903. W. E. KOCH & .T. W. MACDONALD. COMBINED DUST GATGHER AND BLAST HEATER.

APPLIGATION FILED .f AN. 301 1902.

N0 MODEL. 2 SHEETS-SHEET 1.

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'No. 720,257. PATENTEDFEB. 10, 1903. w. E. KOCH & J. w. MAGDONALD.

COMBINED DUST GATOHER AND BLAST HEATER.

APPLICATION FILED JAN. 30, 1902. 10 MODEL. 2 SHEETS-SHEET 2.

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& v m1 m3 UNITED STATES .iP-ATENT OFFICE.

WALTER E. KOCH AND JOHN W. MACDONALD, OF PITTSBURG, PENNSYL- VANIA; SAID KOCH ASSIGNOR TO SAID MACDONALD.

COMBINED DUST-CATCHER .AND BLAST-HEATER.

SPECIFICATION forming part of Letters Patent No. 720,257, dated February 10, 1903.

Application filed January 30, 1902. Serial No. 91,842- (No model.)

To aZZ whom; it may concern.-

Be it known that we, WALTER E. KOCH and JOHN W. MAoDoNALD, of Pittsburg, Allegheny county, Pennsylvania, have invented anew and useful Combined Dust-Catcher and Blast-Heater, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings, forming part of this specification, in which- Figure l is a sectional side elevation of a smelting plant provided with our improved blast-heater and fume-arrester; and Fig. 2 is a top plan view of the same, partly broken away.

Our invention relates to the dust-catchers or fume-arresters from smelting-furnaces in which the air-blast for the smelting-furnace is heated; and its objectsare to improve the construction of the dust-catcher and blast-heater, to reduce the friction of the blast in the blastwall is in the form of an arch havinga lower.

opening leading into a large chamber 10, having upper and lower transverse boxes 11, arranged alternately and connected by inclined pipes 12. The upper boxes are provided with removable covers 13, which are clamped in place, and the pipes 12 are slid down through the holes in the upper boxes, their lower ends resting in seats surrounding the holes in the lower boxes. 'After the pipes are inserted asbestos, sal-ammoniac, and metal filings are packed around both of their ends, and if a pipe becomes broken or injured it can easily be drawn up through the upper box, whose cover is removed, and another inserted and secured in the same manner. We have found that by using enlarged boxes at points where the air-currents are changed in direction the friction is greatly reduced and the blast may be forced into the smelter with much less pressure than is now used.

Between the lower boxes in the large chamnel '26 with a fritting-furnace 27, which has an outlet-flue 28, leading its gases into the first dust-catcher chamber. The large dustcatcher chamber containing the blast-heating boxes'and pipes connects through an end opening 29 with a similar chamber 30, extending parallel and alongside it and containing similar boxes and pipes, the latter boxes,

however, being smaller and with fewer connecting pipes. chamber 30 is connected with the top box of the next chamber, so that the air forced in by blower 31 passes through the pipes and boxes in the chamber 30, and-thence as it expands under heat into the larger boxes and area of connecting-pipes inthe parallel chamber, and thence through pipe 32, leading to the bustle-pipe of the smelter. The outletflue 33 for the boiler 34 of the plant discharges into the chamber 30, so that the waste gases from the boiler unite with those from the fritting-furnace and pass to the stack-flue 35.

The advantages of our invention result fromthe peculiar form and arrangement of the dust-catcher and blast-heater, the other parts of the apparatus forming no part of the present invention. and'being described and claim ed in the copending application of Walter E. Koch, Serial No. 91,816, filed January 30, 1902. The large amount of friction created at the bend of blast-heaters heretofore used is reduced, with a corresponding reduction of power required for driving the blast through the heater. The parallel arrangement of the chambers is compact, all heated Waste gases are utilized, and the deposited discharges of dust and ore are continuously withdrawn.

Many changes may be made in the form and arrangement of the parts without depart- The last upper box of the iug from our invention as defined in the claims.

We claim- 1. In smelting plants, a blast-heater having oppositely-located boxes connected by pipes, removable covers for the boxes opposite to the ends of the pipes, a heating-chamber containing the boxes and pipes, and means for forcinga blast through said heating-channels; substantially as described.

2. The combination with a smeltingfurnace, of a blast-heater connected thereto, said heater having oppositely-located boxes connected by pipes, a heating-chamber containing the boxes and pipes, and means for forcing a blast through said heating-channels, the area of the blast-channels being increased toward the smelter end; substantially as described.

3. A blast-heater comprising a chamber connected with the downtake of a furnace, upper and lower staggered boxes arranged alternately in the heating-chamber, inclined pipes connecting said boxes, and means for forcing the blast through the boxes and pipes; substantially as described.

4. A blast-heater, comprising a chamber connected with the downtake of a furnace, upper and lower boxes arranged alternately in the heating-chamber, inclined pipes connecting said boxes, the upperstaggered boxes having top removable closures for openings through which the pipes may be inserted or removed, and means for forcing the blast through the boxes and pipes; substantially as described.

5. A blast-heater, a smelting-furnace having a downtake connected to the heater, and

a boiler-having its flue connected to the heater arranged to pass the waste products thereinto to join with those from the smelter downcomer; substantially as described.

6. A blastheater having upper and lower boxes with connecting pipes, collectingtroughs between the lower boxes, feed-screws in the troughs, and means for actuating said feed-screws; substantially as described.

7. A blast-heater having two parallel chambers arranged side by side and connected together at one end, upper and lower boxes in said chambers connected by pipes, an airblast connection at one end of the series, an outlet at the outer end leading to the furnace, and a down-comer from the furnace arranged to discharge gases into the blast-heating chambers; substantially as described.

8. A dust-catcher and blast-heater having means for heating the blast and provided with transverse collecting-boxes, feed-screws in said boxes, a common trough at the end of the boxes, at feed-screw within said common trough and connections for driving said feedscrews; substantially as described.

9. A blast-heater and dust-catcher having two chambers each containing blast-heating apparatus, a furnace having a down-comer discharging into one chamber, and a boiler having its outlet-flue connected to the other chamber to combine its gases with those of the down-comer; substantially as described.

In testimony whereof we have hereunto set our hands.

WALTER E. KOCH. JOHN W. MACDONALD.

Witnesses:

L. A. CONNER, J r., L. M. REDMAN. 

